The objectives of this study is to obtain detailed structural data on RNA tumor viruses and to relate the structure with biological functions of the viruses. The specific projects are: (a) To study the function of viral phosphoproteins by studying RNA protein binding and transcription in vitro. (b) To understand the mechanism of deletion of sarcoma gene by studying the structure of RNA genomes of transformation-defective viruses using polyacrylamide gel electrophoresis and heteroduplex mapping. (c) To study the structure of glycoproteins and their modification by the host cells. BIBLIOGRAPHIC REFERENCE: Moscovici, C., M.G. Moscovici, H. Jimenez, M.M.C. Lai, M.J. Hayman and P.K. Vogt. (1977): Continuous tissue culture cell lines derved from chemically induced tumors of Japanese quail. Cell, in press.